Adhesive compositions and articles, and methods of making and using the same

ABSTRACT

An adhesive composition includes a first acrylic polymer preparable from first components and a second acrylic polymer. The first components comprising i) a branched first alkyl (meth)acrylate having from 4 to 22 carbon atoms, and ii) at least one of acrylic acid and methacrylic acid. The second acrylic polymer is preparable from second components comprising iii) at least one second alkyl (meth)acrylate having from 4 to 22 carbon atoms, iv) a (meth)acrylamide represented by the formula 
     
       
         
         
             
             
         
       
     
     wherein R 1  is H or methyl, and R 2  and R 3  each independently represents H or an alkyl group having from 1 to 8 carbon atoms, or taken together R 2  and R 3  may form a divalent alkylene group having from 4 to 6 carbon atoms, and v) at least one high T g  macromer having a terminal free-radically polymerizable unsaturated group, the high T g  macromer having a T g  of at least 45° C. Based on the combined total weight of the at least one first acrylic polymer and the at least one second acrylic polymer, the at least one second acrylic polymer is present at a level of from 5 to 40 percent by weight. Methods of making the adhesive composition are also disclosed.

TECHNICAL FIELD

The present disclosure broadly relates to adhesive compositions, morespecifically pressure-sensitive adhesive compositions, and methods fortheir preparation.

BACKGROUND

Pressure-sensitive adhesives (PSAs) are used for many applications. Theygenerally require a balance of adhesion and cohesiveness to adhere wellto various types of substrates, and to remove cleanly after a longperiod of adhesion. One type of PSAs, hot-melt PSAs (HMPSAs), has gainedpopularity over the years.

According to the Pressure-Sensitive Tape Council, pressure-sensitiveadhesives (PSAs) are known to possess properties including thefollowing: (1) aggressive and permanent tack, (2) adherence with no morethan finger pressure, (3) sufficient ability to hold onto an adherend,and (4) sufficient cohesive strength to be removed cleanly from theadherend. Materials that have been found to function well as PSAsinclude polymers designed and formulated to exhibit the requisiteviscoelastic properties resulting in a desired balance of tack, peeladhesion, and shear holding power. PSAs are characterized by beingnormally tacky at room temperature (e.g., 20° C.). Materials that aremerely sticky or adhere to a surface do not constitute a PSA; the termPSA encompasses materials with additional viscoelastic properties.

These requirements for pressure-sensitive adhesives are assessedgenerally by means of tests which are designed to individually measuretack, adhesion (peel strength), and cohesion (shear holding power), asnoted by A. V. Pocius in Adhesion and Adhesives Technology: AnIntroduction, 2nd Ed, Hanser Gardner Publication, Cincinnati, Ohio,2002. These measurements taken together constitute the balance ofproperties often used to characterize a PSA.

Hot-melt pressure-sensitive adhesives (hereinafter HMPSAs) are widelyused in industry. HMPSAs are essentially 100 percent solids systems.Usually, such systems have no more than about 5 percent organic solventsor water, more typically no more than about 3 percent organic solventsor water. Among hot-melt adhesive chemistries, (meth)acrylates (i.e.,methacrylates and/or acrylates) are one of the most prominent.(Meth)acrylates have evolved as a preferred class of adhesives due totheir clarity, permanence of properties over time, and versatility ofadhesion, to name just a few of their benefits.

Typically, acrylic HMPSAs are crosslinked in order to provide desirableshear properties, and various techniques have been used. One method ofcrosslinking acrylic HMPSAs involves using actinic (e.g.,electromagnetic or particulate) radiation, typically ultraviolet (UV)light or electron beam. Another method involves chemical crosslinkingthrough covalent and/or ionic bonds

SUMMARY

Advantageously the present disclosure provides for adhesive compositionswith improved cohesive strength of adhesives such as, e.g., PSAs andHMPSAs without the need for a separate radiation cross-linking step. Bycombining a second acrylic polymer comprising one or more lower glasstransition temperature (lower T_(g)) free-radically polymerizablemonomer(s), a basic monomer, and a relatively higher glass transitiontemperature (higher T_(g)) macromer and a first acrylic polymercomprising a lower T_(g) monomer and a (meth)acrylic acid monomer toform adhesive compositions according to the present disclosure, thecohesive strength of these adhesive compositions is greatly improvedcompared to that of comparable conventional adhesive compositions thatrequire a secondary covalent cross-linking step during manufacture tobuild cohesive strength. Adhesive compositions (e.g., HMPSAs) accordingto the present disclosure achieve excellent shear strength for longperiods, even at elevated temperature (e.g., 70° C.). Unexpectedly, thisis achieved even though there is no or very little gel content presentin adhesive compositions according to the present disclosure. In onespecific embodiment, the second acrylic polymer is polymerized and thenblended into the component mixture for the first acrylic polymer and ispresent during the polymerization of the first acrylic polymer.

In one aspect, the present disclosure provides an adhesive compositioncomprising:

-   -   at least one first acrylic polymer preparable by free-radical        polymerization of first components comprising:        -   i) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms; and        -   ii) at least one of acrylic acid and methacrylic acid;    -   at least one second acrylic polymer preparable by free-radical        polymerization of second components comprising:        -   iii) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   iv) at least one (meth)acrylamide represented by the formula

-   -   -   -   wherein R¹ is H or methyl; and            -   R² and R³ independently represents H or an alkyl group                having from 1 to 8 carbon atoms, or taken together R²                and R³ may form a divalent alkylene group having from 4                to 6 carbon atoms; and

        -   iv) at least one high T_(g) macromer having a terminal            free-radically polymerizable unsaturated group, wherein the            high T_(g) macromer has a T_(g) of at least 45° C.,            wherein based on the combined total weight of the at least            one first acrylic polymer and the at least one second            acrylic polymer, the at least one second acrylic polymer is            present at a level of from 5 to 40 percent by weight.

In another aspect, the present disclosure provides a method of making anadhesive composition, the method comprising mixing at least one firstacrylic polymer with at least one second acrylic polymer in the presenceof organic solvent, wherein:

-   -   each first acrylic polymer is preparable by free-radical        polymerization of first components comprising:        -   i) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms; and        -   ii) at least one of acrylic acid and methacrylic acid;    -   each second acrylic polymer is preparable by polymerization of        second components comprising:        -   iii) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   iv) at least one (meth)acrylamide represented by the formula

-   -   -   -   wherein R¹ is H or methyl; and            -   R² and R³ independently represents H or an alkyl group                having from 1 to 8 carbon atoms, or taken together R²                and R³ may form a divalent alkylene group having from 4                to 6 carbon atoms; and

        -   v) at least one high T_(g) macromer having a terminal            free-radically polymerizable unsaturated group, wherein the            high T_(g) macromer has a T_(g) of at least 45° C.,            wherein based on the combined total weight of the at least            one first acrylic polymer and the at least one second            acrylic polymer, the at least one second acrylic polymer is            present at a level of from 5 to 40 percent by weight.

In yet another aspect, the present disclosure provides an adhesivecomposition comprising a polymerized reaction product of componentscomprising:

-   -   a) first components of a first acrylic polymer comprising:        -   i) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   ii) at least one of acrylic acid and methacrylic acid; and    -   b) at least one second acrylic polymer preparable by        polymerization of second components comprising:        -   iii) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   iv) at least one (meth)acrylamide represented by the formula

-   -   -   -   wherein R¹ is H or methyl; and            -   R² and R³ independently represents H or an alkyl group                having from 1 to 8 carbon atoms, or taken together R²                and R³ may form a divalent alkylene group having from 4                to 6 carbon atoms; and

        -   v) at least one high T_(g) macromer having a terminal            free-radically polymerizable unsaturated group, wherein the            high T_(g) macromer has a T_(g) of at least 45° C.; and            wherein, based on the combined total weight of the            components a) and b), second acrylic polymer b) is present            at a level of from 5 to 40 percent by weight.

In yet another aspect, the present disclosure provides an extrudableadhesive pouch comprising an adhesive composition according to thepresent disclosure sealed within a thermoplastic pouch.

In yet another aspect, the present disclosure provides a method ofmaking an extrudable adhesive pouch, the method comprising:

-   -   providing a sealed thermoplastic pouch containing a        polymerizable adhesive precursor composition comprising:        -   a) first components of a first acrylic polymer comprising:            -   i) at least one alkyl (meth)acrylate having from 4 to 22                carbon atoms;            -   ii) at least one of acrylic acid and methacrylic acid;                and        -   b) at least one second acrylic polymer preparable by            polymerization of second components comprising:            -   iii) at least one alkyl (meth)acrylate having from 4 to                22 carbon atoms;            -   iv) at least one (meth)acrylamide represented by the                formula

-   -   -   -   -   wherein R¹ is H or methyl; and

            -   R² and R³ independently represents H or an alkyl group                having from 1 to 8 carbon atoms, or taken together R²                and R³ may form a divalent alkylene group having from 4                to 6 carbon atoms; and

            -   v) at least one high T_(g) macromer having a terminal                free-radically polymerizable unsaturated group, wherein                the high T_(g) macromer has a T_(g) of at least 45° C.;                and

    -   wherein, based on the combined total weight of the components a)        and b), second acrylic polymer b) is present at a level of from        5 to 40 percent by weight; and

at least partially polymerizing the polymerizable adhesive precursorcomposition.

As used herein, the prefix “(meth)acryl” refers to acryl and/ormethacryl. For example, (meth)acrylic acid refers to acrylic acid and/ormethacrylic acid.

As used herein, the term “monomer” refers to a compound having at leastone free-radically polymerizable group, unless otherwise specified.

As used herein, the term “preparable by” means that the subject mattercan be “prepared by” the specified method, or it can be preparedaccording to some other method that gives the same result.

As used herein “T_(g)” refers to glass transition temperature, which canbe determined by known techniques such as, for example, by differentialScanning Calorimetry (DSC); for example, according to ASTM test methodE1356-08 (Reapproved 2014) “Standard Test Method for Assignment of theGlass Transition Temperatures by Differential Scanning Calorimetry”.

Features and advantages of the present disclosure will be furtherunderstood upon consideration of the detailed description as well as theappended claims.

DETAILED DESCRIPTION

Adhesive compositions according to the present disclosure includecomponents with acidic and basic groups that interact to providecoupling between the first and second acrylic polymers that can resultin excellent shear strength over long periods, even at elevatedtemperature (e.g., 70° C.).

In some embodiments, the adhesive compositions comprise a mixture of atleast one first acrylic polymer and at least one second acrylic polymer.Based on the combined total weight of the at least one first acrylicpolymer and the at least one second acrylic polymer, the at least onesecond acrylic polymer is present at a level of from 5 to 40 percent byweight, preferably from 10 to 30 percent by weight, and even morepreferably from 10 to 25 percent by weight.

The first acrylic polymer(s) can be prepared by free-radicalpolymerization of first components comprising the components: i) atleast one first alkyl (meth)acrylate having from 4 to 22 carbon atoms;ii) at least one of acrylic acid and methacrylic acid. Based on thetotal weight of components i) and ii), the first components comprise 85to 99 percent by weight of component i) and 1 to 15 percent by weight ofcomponent ii). In some embodiments, based on the total weight ofcomponents i) and ii), the first components comprise 90 to 99 percent byweight of component i) and 1 to 10 percent by weight of component ii),or even 95 to 99 percent by weight of component i) and 1 to 5 percent byweight of component ii).

Exemplary useful alkyl (meth)acrylates used herein have from 4 to 22carbon atoms, preferably from 7 to 22 carbon atoms, and more preferablyfrom 9 to 20 carbon atoms. The alkyl group may be linear or branched,and may contain one or more rings (e.g., formed of carbon and optionallyone or more N, S, and/or O atoms). Exemplary suitable alkyl(meth)acrylates include n-butyl (meth)acrylate, isobutyl (meth)acrylate,pentyl (meth)acrylate, 2-methylbutyl (meth)acrylate, isoamyl(meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, phenylmeth(acrylate), benzyl meth(acrylate), 2-ethylhexyl (meth)acrylate,n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl(meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl(meth)acrylate, dodecyl (meth)acrylate, isobornyl (meth)acrylate,isostearyl acrylate, octadecyl (meth)acrylate, 2-methylbutyl(meth)acrylate, 4-methyl-2-pentyl (meth)acrylate, 2-ethylhexyl(meth)acrylate, 2-methylhexyl (meth)acrylate, isooctyl (meth)acrylate,2-octyl (meth)acrylate, isononyl (meth)acrylate, isoamyl (meth)acrylate,decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate,2-propylheptyl (meth)acrylate, isotridecyl (meth)acrylate, stearyl(meth)acrylate, isostearyl (meth)acrylate, as well as (meth)acrylic acidesters of Guerbet alcohols having 12 to 22 carbon atoms as described inPCT Pat. Appln. Publ. WO 2011/119363 A1 (Clapper et al.). The amount ofalkyl (meth)acrylate is often at least 75 mole percent of the firstcomponents. For example, the first components can contain at least 80mole percent, at least 85 mole percent, at least 90 mole percent, or atleast 95 mole percent alkyl (meth)acrylate having from 4 to 22 carbonatoms based on total moles of monomer(s) in the first component mixture.

The first components are combined prior to polymerization, resulting intheir incorporation into the first acrylic polymer. In the event thatmultiple first acrylic polymers are present, they may be madeindependently or simultaneously, for example.

Additional optional components may also be added prior to polymerizationresulting in their incorporation in the first acrylic polymer(s).Examples of such optional components include nitrogen-free polarmonomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, and 3-hydroxypropyl (meth)acrylate. If included, thesepolar monomers are preferably included in an amount of less than 20percent by weight, more preferably less than 10 percent by weight, oreven less than 5 percent by weight.

The first acrylic polymer preferably has a glass transition temperature(T_(g)) no greater than 20° C., preferably no greater than 10° C., nogreater than 0° C., no greater than −10° C., no greater than −20° C., nogreater than −30° C., no greater than −40° C., or even no greater than−50° C.

The second acrylic polymer(s) can be prepared by free-radicalpolymerization of second components comprising: iii) at least one alkyl(meth)acrylate having from 4 to 22 carbon atoms; iv) at least one(meth)acrylamide represented by the Formula I (below):

wherein R¹, R², and R³ are as previously defined; and v) at least onehigh T_(g) macromer having a terminal free-radically polymerizableunsaturated group. The high T_(g) macromer has a T_(g) of at least 45°C., preferably at least 60° C., at least 80° C., at least 85° C., oreven at least 90° C.

The amount of alkyl (meth)acrylate having from 4 to 22 carbon atoms isoften at least 35 weight percent of the components of the second acrylicpolymer. For example, the components of the second acrylic polymer cancontain from 35 to 95 weight percent, from 50 to 90 weight percent, orfrom 70 to 90 weight percent of the alkyl (meth)acrylate having from 4to 22 carbon atoms based on the total weight of the second components.

Exemplary (meth)acrylamides represented by Formula 1 include thosewherein R¹ represents H or methyl, and R² and R³ independentlyrepresents H or an alkyl group having from 1 to 8 carbon atoms, (e.g.,methyl, ethyl, propyl, isopropyl, n-butyl, iso-butyl, or tert-butyl), ortaken together R² and one R³ may form a divalent alkylene group havingfrom 4 to 6 carbon atoms (e.g., ethan-1,2-diyl (i.e., —CH₂CH₂—),propan-1,3-diyl, 1,4-butan-1,4-diyl, cyclohexan-1,4-diyl). Examples ofsuitable (meth)acrylamides according to Formula I include(meth)acrylamide, N-methyl(meth)acrylamide,N,N-dimethyl(meth)acrylamide, N-ethyl(meth)acrylamide,N,N-dimethyl(meth)acrylamide, N-methyl-N-propyl(meth)acrylamide,N,N-dipropyl(meth)acrylamide, N-butyl(meth)acrylamide,N,N-dibutyl(meth)acrylamide, 1-(1-piperidinyl)-2-propen-1-one, and1-(1-piperidinyl)-2-methyl-2-propen-1-one.

The amount of (meth)acrylamides according to Formula I in the secondcomponents is preferably from 1 to 25 weight percent, more preferably 1to 15 weight percent, and even more preferably from 1 to 10 weightpercent, based on the total weight of the second components.

Useful high T_(g) macromers are polymers that have a terminalfree-radically polymerizable double bond such as a vinyl group, acrylategroup, or methacrylate group, and have a T_(g) of at least 45° C.,preferably at least 60° C., preferably at least 80° C., more preferablyat least 90° C., or even at least 100° C. Such macromers are known, andmay be prepared by the methods disclosed in U.S. Pat. No. 3,786,116(Milkovich et al.) and U.S. Pat. No. 3,842,059 (Milkovich et al.), aswell as Y. Yamashita et al., Polymer Journal, 1982, vol. 14, pp.255-260, and K. Ito et al., Macromolecules, 1980, vol. 13, pp. 216-221.Generally, the T_(g) of the macromer is determined by the polymer chain.In order to exhibit a desired glass transition temperature, the macromerpreferably has a molecular weight of from 500 to 50000 g/mole. Thepolymeric portion of the macromer may comprise, e.g., atactic polymethylmethacrylate (T_(g)=105° C.), polystyrene (T_(g)=100° C.), polyisobornylacrylate (T_(g)=94° C.), polyisobornyl methacrylate (T_(g)=110° C.),cyclohexyl methacrylate (T_(g)=92° C.). The T_(g) values quoted here arelimiting values at high molecular weight for these polymers. In someembodiments, the high T_(g) macromer is free of nitrogen atoms, althoughthis is not a requirement. The high T_(g) macromer may be a homopolymerend-capped with a polymerizable unsaturated group. Likewise, the highT_(g) macromer may be a copolymer end-capped with a polymerizableunsaturated group, as long as its T_(g) is sufficiently high.

Additional optional monomers may also be added to the second componentsprior to polymerization resulting in their incorporation in the secondacrylic polymer(s). Examples of such optional monomers include polarmonomers such as hydroxyalkyl (meth)acrylates (e.g., 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl(meth)acrylate, and 4-hydroxybutyl (meth)acrylate). Exemplary N-vinylpolar monomers include N-vinylcaprolactam, N-vinylacetamide,N-vinylformamide, and N-vinyl-2-pyrrolidone).

Exemplary polar monomers with an ether group include alkoxylated alkyl(meth)acrylates such as ethoxyethoxyethyl (meth)acrylate, 2-methoxyethyl(meth)acrylate, and 2-ethoxyethyl (meth)acrylate; and poly(alkyleneoxide) (meth)acrylates such as poly(ethylene oxide) (meth)acrylates andpoly(propylene oxide) (meth)acrylates. The poly(alkylene oxide)acrylates are often referred to as poly(alkylene glycol)(meth)acrylates. These monomers can have any suitable end group such asa hydroxyl group or an alkoxy group. For example, when the end group isa methoxy group, the monomer can be referred to as methoxy poly(ethyleneglycol) (meth)acrylate.

If present, the optional polar monomer(s) can be included in an amountup to 25 weight percent based on total weight of components in the firstor second components. In some embodiments, the polar monomer is presentin an amount up to 20 weight percent, up to 15 weight percent, or up to10 weight percent based on the total weight of components in the firstor second components.

Any other components compatible with (e.g., miscible with) the first orsecond components can optionally be included in formation of the firstacrylic polymer and/or the second acrylic polymer. Examples of othercomponents include various aryl (meth)acrylate (e.g., phenyl(meth)acrylate), vinyl ethers, vinyl esters (e.g., vinyl acetate),olefinic monomers (e.g., ethylene propylene, or butylene), styrene, andstyrene derivatives (e.g., alpha-methylstyrene). Still other examplecomponents are aryl substituted alkyl (meth)acrylates or alkoxysubstituted alkyl (meth)acrylates such as 2-biphenylhexyl(meth)acrylate, benzyl (meth)acrylate, and 2-phenoxyethyl(meth)acrylate. In many embodiments, the (meth)acrylate is an acrylate.The mixture of first components typically does not include a monomerwith multiple (meth)acryloyl groups or multiple free-radicallypolymerizable unsaturated groups. The relative amounts of componentsiii) (i.e., the alkyl (meth)acrylate), iv) (i.e., the optionallysubstituted (meth)acrylamide), and v) (i.e., the high T_(g) macromer)used to form the second acrylic polymer may vary. In some preferredembodiments, the second acrylic polymer comprises 30 to 94 percent byweight of component iii), 1 to 10 percent by weight of component iv),and 5 to 60 percent by weight of component v), based on the total weightof the components iii), iv), and v). In other preferred embodiments,based on the total weight of the first and second acrylic polymers, themacromer comprises from 1 to 15 percent by weight of the first andsecond acrylic polymers.

Typically, the first and second acrylic polymers can be made bypolymerization of the corresponding first or second components, eachwith a respective effective amount of a free-radical initiator systeminto the first and second components, although other methods such asactinic electromagnetic radiation (e.g., ultraviolet, visible light, andgamma radiation) and/or an electron beam may also be used, for example.If a thermal initiator and/or a photoinitiator is used it is generallyused in at least an effective amount (e.g., from 0.01 to 10 percent byweight, preferably 0.1 to 5 percent by weight) based on the totalcombined weight of the first and/or second components with which it iscombined, although this is not a requirement.

Useful free-radical initiator systems can include a photoinitiatorand/or a thermal initiator. Suitable thermal initiators include variousazo compound such as those commercially available under the tradedesignation VAZO from E. I. DuPont de Nemours Co. (Wilmington, Del.)including VAZO 67, which is 2,2′-azobis(2-methylbutane nitrile), VAZO64, which is 2,2′-azobis(isobutyronitrile), VAZO 52, which is(2,2′-azobis(2,4-dimethylpentanenitrile), and VAZO 88, which is1,1′-azobis(cyclohexanecarbonitrile); various peroxides such as benzoylperoxide, cyclohexane peroxide, lauroyl peroxide, di-tert-amyl peroxide,tert-butyl peroxybenzoate, di-cumyl peroxide, and peroxides commerciallyavailable from Atofina Chemical, Inc. (Philadelphia, Pa.) under thetrade designation LUPERSOL (e.g., LUPERSOL 101, which is2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, and LUPERSOL 130, which is2,5-dimethyl-2,5-di-(tert-butylperoxy)-3-hexyne); various hydroperoxidessuch as tert-amyl hydroperoxide and tert-butyl hydroperoxide; andmixtures thereof.

In many embodiments, a photoinitiator is used. Some exemplaryphotoinitiators are benzoin ethers (e.g., benzoin methyl ether orbenzoin isopropyl ether) or substituted benzoin ethers (e.g., anisoinmethyl ether). Other exemplary photoinitiators are substitutedacetophenones such as 2,2-diethoxyacetophenone or2,2-dimethoxy-2-phenylacetophenone (commercially available under thetrade designation IRGACURE 651 from BASF Corp. (Florham Park, N.J.) orunder the trade designation ESACURE KB-1 from Sartomer (Exton, Pa.).Still other exemplary photoinitiators are substituted alpha-ketols suchas 2-methyl-2-hydroxypropiophenone, aromatic sulfonyl chlorides such as2-naphthalenesulfonyl chloride, and photoactive oximes such as1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. Other suitablephotoinitiators include, for example, 1-hydroxycyclohexyl phenyl ketone(commercially available under the trade designation IRGACURE 184),bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (commercially availableunder the trade designation IRGACURE 819),1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one(commercially available under the trade designation IRGACURE 2959),2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (commerciallyavailable under the trade designation IRGACURE 369),2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (commerciallyavailable under the trade designation IRGACURE 907), and2-hydroxy-2-methyl-1-phenyl propan-1-one (commercially available underthe trade designation DAROCUR 1173 from Ciba Specialty Chemicals Corp.(Tarrytown, N.Y.).

The first and/or second components may optionally be combined with achain transfer agent to control the molecular weight of the resultantacrylic copolymer. Examples of useful chain transfer agents include, butare not limited to, carbon tetrabromide, alcohols (e.g., ethanol andisopropanol), mercaptans or thiols (e.g., lauryl mercaptan, butylmercaptan, ethanethiol, isooctyl thioglycolate, 2-ethylhexylthioglycolate, 2-ethylhexyl mercaptopropionate, ethylene glycolbisthioglycolate, and tert-dodecyl mercaptan), and mixtures thereof. Ifused, the polymerizable mixture may include up to 0.5 weight percent ofa chain transfer agent based on a total weight of components. Forexample, the first reaction mixture can contain 0.005 to 0.5 weightpercent, 0.01 to 0.5 weight percent, 0.01 to 0.2 weight percent, or 0.01to 0.1 weight percent chain transfer agent.

Although any known method of making acrylic copolymers can be used, insome embodiments, it is desirable to minimize the use of organicsolvents that will need to be removed later. One suitable method is toform the first (meth)acrylate within a polymeric pouch that has beenpurged to remove oxygen. This method, which is further described in U.S.Pat. No. 5,804,610 (Hamer et al.) and U.S. Pat. No. 6,294,249 (Hamer etal.), is particularly advantageous when the first acrylic polymer issubsequently processed using hot melt processing methods.

In this polymerization method, the various components of the reactionmixture can be sealed in a packaging material (e.g., a polymeric pouch)that does not dissolve in the presence of the first reaction mixture andthat is capable of transmitting ultraviolet radiation. The packagingmaterial is usually selected to have a melting point at or below theprocessing temperature of the first acrylic polymer, which is thetemperature at which this material will flow. The packaging materialoften has a melting point no greater than 200° C., no greater than 175°C., or no greater than 150° C. The packaging material is often preparedfrom a flexible thermoplastic polymeric film of ethylene-vinyl acetate,ethylene-acrylic acid, polypropylene, polyethylene, polybutadiene, orionomeric materials. The polymeric films often have a thickness of atleast 0.01 millimeters, at least 0.02 millimeters, or at least 0.03millimeters. The thickness is often up to 0.30 millimeters, up to 0.25millimeters, up to 0.20 millimeters, up to 0.15 millimeters, or up to0.10 millimeters. Thinner films are often desired to minimize the amountof the packaging material that is added into the adhesive composition.The amount of the packaging material is typically at least 0.5 weightpercent of the total weight of the packaging material and the firstreaction mixture. For example, this amount is often at least 1 weightpercent, at least 2 weight percent, or even at least 3 weight percent.The amount can be up to 20 weight percent, up to 15 weight percent, upto 10 weight percent, or up to 5 weight percent based on the totalweight of the packaging material and the first reaction mixture. In someembodiments, the amount is in a range of 1 to 20 weight percent, 1 to 10weight percent, or 2 to 10 weight percent based on the total weight ofthe packaging material and the first reaction mixture.

The packaging material is often in the form of a polymeric pouchprepared from two lengths of thermoplastic film that are heat sealedtogether across the bottom and each lateral edge. The first reactionmixture is placed within the polymeric pouch and the polymeric pouch isthen heat sealed across the top to completely surround the firstreaction mixture. Prior to sealing the top of the polymeric pouch, it istypically desirable to remove as much air as possible.

A small amount of air can be tolerated if the amount is not sufficientto substantially interfere with the polymerization reaction.

The polymerization of the first reaction mixture occurs upon exposure toUV radiation. Suitable UV sources often have at least 60 percent, atleast 65 percent, at least 70 percent, or at least 75 percent of theemission spectra within the range of 280 to 400 nanometers and have anintensity within the range of 0.1 to 25 mW/cm 2. The temperature of thereaction mixture is often controlled by immersing the sealed polymericpouch in a water bath or heat transfer fluid controlled at a temperaturein a range of 5° C. to 50° C., in a range of 5° C. to 40° C., in a rangeof 5° C. to 30° C., or in a range of 5° C. to 20° C.

The first and second acrylic polymers, and any desired additionalcomponents can be combined and mixed by any suitable technique. Oneuseful techniques is to mix the polymers in a solvent (e.g., an organicsolvent), optionally with subsequent removal of at least a portion ofthe solvent. Examples of suitable solvents include ketones (e.g., methylacetate, ethyl acetate, isopropyl acetate, methyl isobutyl ketone,methyl isoamyl ketone, methyl n-amyl ketone, diisobutyl ketone, andmethyl n-propyl ketone), esters (e.g., n-propyl acetate, isobutylacetate, t-butyl acetate, isobutyl isobutyrate, methoxyisopropylacetate, ethylhexyl acetate, butoxyethyl acetate, ethoxyethoxyethylacetate, ethylene glycol diacetate, butoxyethoxyethyl acetate,2,2,4-trimethyl-1,3-pentandiol monoisobutyrate, and n-butyl acetate),ethers (e.g., methoxyisopropyl alcohol, propoxyethyl alcohol,2-ethoxyethanol, tetrahydrofuran), and alcohols (e.g., butoxyethylalcohol, 2-methoxyethoxyethyl alcohol, ethoxyethoxyethyl alcohol,propoxyethoxyethyl alcohol, butoxyethoxyethyl alcohol,2-ethylhexoxyethyl alcohol, ethyl alcohol, isopropyl alcohol, n-propylalcohol, isobutyl alcohol, n-butyl alcohol, and 2-ethylhexyl alcohol).

In many embodiments, the polymerization occurs with little or no organicsolvent present. If used, the organic solvent is often present in anamount less than 10 weight percent, less than 5 weight percent, lessthan 4 weight percent, less than 3 weight percent, less than 2 weightpercent, or less than 1 weight percent based on the total weight of thefirst reaction mixture. If used, any organic solvent typically isremoved at the completion of the polymerization reaction.

The first and second acrylic polymers can be combined to form anadhesive composition wherein the at least one second acrylic polymer ispresent at a level of from 5 to 40 percent by weight, based on thecombined total weight of the at least one first acrylic polymer and theat least one second acrylic polymer. In some embodiments, the at leastone second acrylic polymer is present at a level of from 10 to 25percent by weight, based on the combined total weight of the at leastone first acrylic polymer and the at least one second acrylic polymer.

In an alternative approach for making such adhesive compositions, thesecond acrylic polymer described above (i.e., a copolymer of alkyl(meth)acrylate, (meth)acrylamide compound, and high T_(g) macromer) canbe combined with the first components described above, and then themixture free-radically polymerized to form the adhesive composition, forexample. Free-radical polymerization can be accomplished, for example,according to the methods described hereinabove.

In addition to the first and second acrylic polymers, adhesivecompositions according to the present disclosure may also include atleast one tackifier. The tackifier is typically selected to be misciblewith both of the first and second acrylic copolymers, although this isnot a requirement. Either solid or liquid tackifiers can be added. Solidtackifiers generally have a number average molecular weight (M_(n)) of10,000 grams per mole or less and a softening point above about 70° C.Liquid tackifiers are viscous materials that have a softening point ofabout 0° C. to about 70° C.

Suitable tackifying resins include rosin resins such as rosin acids andtheir derivatives (e.g., rosin esters); terpene resins such aspolyterpenes (e.g., alpha pinene-based resins, beta pinene-based resins,and limonene-based resins) and aromatic-modified polyterpene resins(e.g., phenol modified polyterpene resins); coumarone-indene resins; andpetroleum-based hydrocarbon resins such as C5-based hydrocarbon resins,C9-based hydrocarbon resins, C5/C9-based hydrocarbon resins, anddicyclopentadiene-based resins. These tackifying resins, if added, canbe hydrogenated to lower their color contribution to thepressure-sensitive adhesive composition. Combinations of varioustackifiers can be used, if desired. In many embodiments, the tackifieris a rosin ester or includes a rosin ester.

Tackifiers that are rosin esters are the reaction products of variousrosin acids and alcohols. These include, but are not limited to, methylesters of rosin acids, triethylene glycol esters of rosin acids,glycerol esters of rosin acids, and pentaerythritol esters of rosinacids. These rosin esters can be hydrogenated partially or fully toimprove stability and reduce their color contribution to thepressure-sensitive adhesive composition. The rosin resin tackifiers arecommercially available, for example, from Eastman Chemical Company(Kingsport, Tenn.) under the trade designations PERMALYN, STAYBELITE,and FORAL as well as from Newport Industries (London, England) under thetrade designations NUROZ and NUTAC. A fully hydrogenated rosin resin iscommercially available, for example, from Eastman Chemical Company underthe trade designation FORAL AX-E. A partially hydrogenated rosin resinis commercially available, for example, from Eastman Chemical Companyunder the trade designation STAYBELITE-E.

Tackifiers that are hydrocarbon resins can be prepared from variouspetroleum-based feed stocks. These feedstocks can be aliphatichydrocarbons (mainly C5 monomers with some other monomers present suchas a mixture of trans-1,3-pentadiene, cis-1,3-pentadiene,2-methyl-2-butene, dicyclopentadiene, cyclopentadiene, andcyclopentene), aromatic hydrocarbons (mainly C9 monomers with some othermonomers present such as a mixture of vinyltoluenes, dicyclopentadiene,indene, methylstyrene, styrene, and methylindenes), or mixtures thereof.Tackifiers derived from C5 monomers are referred to as C5-basedhydrocarbon resins while those derived from C9 monomers are referred toas C9-based hydrocarbon resins. Some tackifiers are derived from amixture of C5 and C9 monomers or are a blend of C5-based hydrocarbontackifiers and C9-based hydrocarbon tackifiers. These tackifiers can bereferred to as C5/C9-based hydrocarbon tackifiers. Any of these resinscan be partially or fully hydrogenated to improve their color andthermal stability.

The C5-based hydrocarbon resins are commercially available from EastmanChemical Company under the trade designations PICCOTAC and EASTOTAC,from Cray Valley (Exton, Pa.) under the trade designation WINGTACK, fromNeville Chemical Company (Pittsburgh, Pa.) under the trade designationNEVTAC LX, and from Kolon Industries, Inc. (South Korea) under the tradedesignation HIKOREZ. The C5-based hydrocarbon resins are commerciallyavailable from Eastman Chemical with various degrees of hydrogenationunder the trade designation EASTOTACK.

The C9-based hydrocarbon resins are commercially available from EastmanChemical Company under the trade designation PICCO, KRISTLEX, PLASTOLYN,and PICCOTAC, and ENDEX, from Cray Valley under the trade designationsNORSOLENE, from Ruetgers N.V. (Belgium) under the trade designationNOVAREZ, and from Kolon Industries, Inc. (South Korea) under the tradedesignation HIKOTAC. These resins can be partially or fullyhydrogenated. Prior to hydrogenation, the C9-based hydrocarbon resinsare often about 40 percent aromatic as measured by proton NuclearMagnetic Resonance. Hydrogenated C9-based hydrocarbon resins arecommercially available, for example, from Eastman Chemical under thetrade designations REGALITE and REGALREX that are 50 to 100 percent(e.g., 50 percent, 70 percent, 90 percent, and 100 percent)hydrogenated. The partially hydrogenated resins typically have somearomatic rings.

Various C5/C9-based hydrocarbon tackifiers are commercially availablefrom Arakawa (Germany) under the trade designation ARKON, from ZeonCorporation (Japan) under the trade designation QUINTONE, from ExxonMobile Chemical (Houston, Tex.) under the trade designation ESCOREZ, andfrom Newport Industries (London, England) under the trade designationsNURES and H-REZ.

Any of the tackifiers may be used in an amount, preferably at least 20weight percent based on a total weight of solids in the adhesivecomposition, although lower amounts may also be useful. As used herein,the term “solids” includes all materials other than water and organicsolvents in the adhesive composition. The main contributors to thesolids are the first and second acrylic polymers, and optionaltackifier. In some embodiments, the amount of tackifier is at least 25weight percent, at least 30 weight percent, or at least 35 weightpercent based on the total weight of solids in the adhesive composition.The amount of the tackifier can be up to 60 weight percent or evenhigher, up to 55 weight percent, up to 50 weight percent, up to 45weight percent, or up to 40 weight percent based on the total weight ofthe solids in the adhesive composition. In some embodiments, thetackifier is present in an amount in a range of 20 to 60 weight percent,in a range of 30 to 60 weight percent, in a range of 20 to 50 weightpercent, in a range of 30 to 50 weight percent, in a range of 20 to 45weight percent, or in a range of 20 to 40 weight percent based on thetotal weight of solids in the adhesive composition.

Further optional components can be added to the adhesive compositionsuch as, for example, heat stabilizers, antioxidants, antistatic agents,plasticizers, thickeners, fillers, pigments, dyes, colorants,thixotropic agents, processing aides, nanoparticles, fibers, andcombinations thereof. Such additives, if present, usually contribute intotal less than 10 weight percent, less than 5 weight percent, less than3 weight percent, or less than 1 weight percent to the solids of theadhesive composition.

The first acrylic polymer, the second acrylic polymer, and the optionaltackifier can be blended together to form the adhesive composition. Anysuitable method of blending these components together can be used. Theblending method can be done in the presence or absence of an organicsolvent. In many embodiments, it can be advantageous to form an adhesivecomposition free or substantially free of an organic solvent. As used inreference to the adhesive composition, the term “substantially free”means that the total solids of the adhesive composition is greater than90 weight percent, greater than 95 weight percent, greater than 97weight percent, greater than 98 weight percent, or greater than 99weight percent based on a total weight of the adhesive composition.

In many embodiments, the blending methods include mixing the variouscomponents in a molten state. Such blending methods can be referred toas hot melt mixing methods or hot melt blending methods. Both batch andcontinuous mixing equipment can be used. Examples of batch methods forblending components of the adhesive composition include those using aBRABENDER (e.g., a BRABENDER PREP CENTER that is commercially availablefrom C.W. Brabender Instruments, Inc. (South Hackensack, N.J.) orBANBURY internal mixing and roll milling equipment, which is availablefrom Farrel Co. (Ansonia, Conn.). Examples of continuous mixing methodsinclude single screw extruding, twin screw extruding, disk extruding,reciprocating single screw extruding, and pin barrel single screwextruding. Continuous methods can utilize distributive elements, pinmixing elements, static mixing elements, and dispersive elements such asMADDOCK mixing elements and SAXTON mixing elements.

A single piece or multiple pieces of hot melt mixing equipment may beused to prepare the adhesive compositions. In some embodiments, it maybe desirable to use more than one piece of hot melt mixing equipment.For example, a first extruder such as a single screw extruder can beused to hot melt process the first acrylic polymer contained within athermoplastic pouch. The output of the first extruder can be fed into asecond extruder such as a twin screw extruder for hot melt mixing thefirst acrylic polymer with the second acrylic polymer, tackifier, orboth.

The output of the hot melt mixing process is a blended adhesivecomposition. This blended adhesive composition can be applied as acoating to a substrate. If a batch apparatus is used, the hot meltblended adhesive composition can be removed from the apparatus andplaced in a hot melt coater or extruder for coating onto a substrate. Ifan extruder is used, the hot melt blended adhesive composition can bedirectly extruded onto a substrate to form a coating.

The extruded adhesive composition is typically deposited on a substrate.Thus, in another aspect, an article is provided. The article includes asubstrate and a coating of the adhesive composition positioned adjacentto the substrate. The adhesive composition is the same as describedabove and includes the first acrylic polymer, the second acrylicpolymer, and the tackifier. As used herein, the term “adjacent” refersto a first layer positioned near the second layer. The first and secondlayers can be in contact or can be separated from each other by anotherlayer. For example, a substrate can be positioned adjacent to theadhesive composition if the substrate contacts the adhesive compositionor is separated from the adhesive composition by another layer such as aprimer layer or surface modification layer that increases the adhesionof the adhesive composition to the substrate. The adhesive compositionis typically applied as a coating to a major surface of the substrateand the article is a substrate coated with the adhesive composition.

Any suitable substrate can be used in the article. For example, thesubstrate can be flexible or inflexible and can be formed from apolymeric material, glass or ceramic material, metal, or combinationthereof. Some substrates are polymeric films such as those prepared frompolyolefins (e.g., polyethylene, polypropylene, or copolymers thereof),polyurethanes, polyvinyl acetates, polyvinyl chlorides, polyesters(polyethylene terephthalate or polyethylene naphthalate),polycarbonates, polymethyl(meth)acrylates (PMMA), ethylene-vinyl acetatecopolymers, and cellulosic materials (e.g., cellulose acetate, cellulosetriacetate, and ethyl cellulose). Other substrates are metal foils,nonwoven materials (e.g., paper, cloth, nonwoven scrims), foams (e.g.,polyacrylic, polyethylene, polyurethane, neoprene), and the like. Forsome substrates, it may be desirable to treat the surface to improveadhesion to the crosslinked composition, crosslinked composition, orboth. Such treatments include, for example, application of primerlayers, surface modification layer (e.g., corona treatment or surfaceabrasion), or both.

In some embodiments, the substrate is a release liner. Release linerstypically have low affinity for the adhesive composition or crosslinkedcomposition. Exemplary release liners can be prepared from paper (e.g.,Kraft paper) or other types of polymeric material. Some release linersare coated with an outer layer of a release agent such as asilicone-containing material or a fluorocarbon-containing material.

The adhesive composition coating can have any desired thickness. In manyembodiments, the adhesive composition coating has a thickness no greaterthan 20 mils (500 micrometers), no greater than 10 mils (250micrometers), no greater than 5 mils (125 micrometers), no greater than4 mils (100 micrometers), no greater than 3 mils (75 micrometers), or nogreater than 2 mils (50 micrometers). The thickness is often at least0.5 mils (12.5 micrometers) or at least 1 mil (25 micrometers). Forexample, the thickness of the adhesive composition coating can be in therange of 0.5 mils (2.5 micrometers) to 20 mils (500 micrometers), in therange of 0.5 mils (5 micrometers) to 10 mils (250 micrometers), in therange of 0.5 mils (12.5 micrometers) to 5 mils (125 micrometers), in therange of 1 mil (25 micrometers) to 3 mils (75 micrometers), or in therange of 1 mil (25 micrometers) to 2 mils (50 micrometers).

Articles with a coating of the adhesive composition have apressure-sensitive adhesive layer and can be used for many applicationstypical of such articles. The substrate adjacent to thepressure-sensitive layer can be selected depending on the particularapplication. For example, the substrate can be a sheeting material andthe resulting article can provide decorative graphics or can be areflective product. In other examples, the substrate can be label stock(the resulting article is a label with an adhesive layer) or tapebacking (the resulting article is an adhesive tape). In yet otherexamples, the substrate can be a release liner and the resulting articlecan be a transfer tape. The transfer tape can be used to transfer thepressure-sensitive adhesive layer to another substrate or surface. Othersubstrates and surface include, for example, a panel (e.g., a metalpanel such as an automotive panel) or a glass window.

Some articles are adhesive tapes. The adhesive tapes can be single-sidedadhesive tapes with the adhesive composition attached to a single sideof the tape backing or can be double-sided adhesive tape with apressure-sensitive adhesive layer on both major surfaces of the tapebacking. At least one of the two pressure-sensitive adhesive layers isthe adhesive composition described above. Double-sided adhesive tapesare often carried on a release liner.

SELECT EMBODIMENTS OF THE PRESENT DISCLOSURE

In a first embodiment, the present disclosure provides an adhesivecomposition comprising:

-   -   at least one first acrylic polymer preparable by free-radical        polymerization of first components comprising:        -   i) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms; and        -   ii) at least one of acrylic acid and methacrylic acid;    -   at least one second acrylic polymer preparable by free-radical        polymerization of second components comprising:        -   iii) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   iv) at least one (meth)acrylamide represented by the formula

-   -   -   -   wherein R¹ is H or methyl; and

        -   R² and R³ independently represents H or an alkyl group            having from 1 to 8 carbon atoms, or taken together R² and R³            may form a divalent alkylene group having from 4 to 6 carbon            atoms; and

        -   v) at least one high T_(g) macromer having a terminal            free-radically polymerizable unsaturated group, wherein the            high T_(g) macromer has a T_(g) of at least 45° C.,            wherein based on the combined total weight of the at least            one first acrylic polymer and the at least one second            acrylic polymer, the at least one second acrylic polymer is            present at a level of from 5 to 40 percent by weight.

In a second embodiment, the present disclosure provides an adhesivecomposition according to the first embodiment, wherein the high T_(g)macromer has a T_(g) of at least 80° C.

In a third embodiment, the present disclosure provides an adhesivecomposition according to the first or second embodiment, wherein the atleast one high T_(g) macromer comprises a polymethyl methacrylatemacromer having a terminal free-radically polymerizable unsaturatedgroup.

In a fourth embodiment, the present disclosure provides an adhesivecomposition according to any one of the first to third embodiments,wherein based on the total weight of components i) and ii), the firstacrylic polymer comprises:

85 to 99 percent by weight of first component i); and

1 to 15 percent by weight of first component ii).

In a fifth embodiment, the present disclosure provides an adhesivecomposition according to any one of the first to fourth embodiments,wherein based on the total weight of the components iii), iv), and v),the second acrylic polymer comprises:

30 to 94 percent by weight of second component iii);

1 to 10 percent by weight of second component iv); and

5 to 60 percent by weight of second component v).

In a sixth embodiment, the present disclosure provides an adhesivecomposition according to any one of the first to fifth embodiments,wherein based on the combined total weight of the at least one firstacrylic polymer and the at least one second acrylic polymer, the secondacrylic polymer comprises from 5 to 40 percent by weight.

In a seventh embodiment, the present disclosure provides an adhesivecomposition according to any one of the first to fifth embodiments,wherein the polymerizable adhesive precursor composition furthercomprises at least one of a tackifier and a plasticizer. In an eighthembodiment, the present disclosure provides a method of making anadhesive composition, the method comprising mixing at least one firstacrylic polymer with at least one second acrylic polymer in the presenceof organic solvent, wherein:

-   -   each first acrylic polymer is preparable by free-radical        polymerization of first components comprising:        -   i) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms; and        -   ii) at least one of acrylic acid and methacrylic acid;    -   each second acrylic polymer is preparable by polymerization of        second components comprising:        -   iii) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   iv) at least one (meth)acrylamide represented by the formula

-   -   -   -   wherein R¹ is H or methyl; and

        -   R² and R³ independently represents H or an alkyl group            having from 1 to 8 carbon atoms, or taken together R² and R³            may form a divalent alkylene group having from 4 to 6 carbon            atoms; and

        -   v) at least one high T_(g) macromer having a terminal            free-radically polymerizable unsaturated group, wherein the            high T_(g) macromer has a T_(g) of at least 45° C.,            wherein based on the combined total weight of the at least            one first acrylic polymer and the at least one second            acrylic polymer, the at least one second acrylic polymer is            present at a level of from 5 to 40 percent by weight.

In a ninth embodiment, the present disclosure provides an adhesivecomposition comprising a polymerized reaction product of componentscomprising:

-   -   a) first components of a first acrylic polymer comprising:        -   i) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   ii) at least one of acrylic acid and methacrylic acid;    -   b) at least one second acrylic polymer preparable by        polymerization of second components comprising:        -   iii) at least one alkyl (meth)acrylate having from 4 to 22            carbon atoms;        -   iv) at least one (meth)acrylamide represented by the formula

-   -   -   -   wherein R¹ is H or methyl; and

        -   R² and R³ independently represents H or an alkyl group            having from 1 to 8 carbon atoms, or taken together R² and R³            may form a divalent alkylene group having from 4 to 6 carbon            atoms; and

        -   v) at least one high T_(g) macromer having a terminal            free-radically polymerizable unsaturated group, wherein the            high T_(g) macromer has a T_(g) of at least 45° C.; and            wherein, based on the combined total weight of the            components a) and b), second acrylic polymer b) is present            at a level of from 5 to 40 percent by weight.

In a tenth embodiment, the present disclosure provides an adhesivecomposition according to the ninth embodiment, wherein the high T_(g)macromer has a T_(g) of at least 80° C.

In an eleventh embodiment, the present disclosure provides an adhesivecomposition according to the ninth or tenth embodiment, wherein the atleast one high T_(g) macromer comprises a polymethyl methacrylatemacromer having a terminal free-radically polymerizable unsaturatedgroup.

In a twelfth embodiment, the present disclosure provides an adhesivecomposition according to any one of the ninth to eleventh embodiments,wherein based on the total weight of components i) and ii), the firstcomponents comprise:

85 to 99 percent by weight of first component i); and

1 to 15 percent by weight of first component ii).

In a thirteenth embodiment, the present disclosure provides an adhesivecomposition according to any one of the ninth to twelfth embodiments,wherein based on the total weight of the components iii), iv), and v),the second acrylic polymer comprises:

30 to 94 percent by weight of second component iii);

1 to 10 percent by weight of second component iv); and

5 to 60 percent by weight of second component v).

In a fourteenth embodiment, the present disclosure provides an adhesivecomposition according to any one of the ninth to thirteenth embodiments,further comprising at least one of a tackifier and a plasticizer.

In a fifteenth embodiment, the present disclosure provides an extrudableadhesive pouch comprising the adhesive composition according to any oneof the ninth to fourteenth embodiments, sealed within a thermoplasticpouch.

In a sixteenth embodiment, the present disclosure provides an adhesivepouch according to the fifteenth embodiment, wherein the thermoplasticpouch comprises an ethylene-vinyl acetate copolymer.

In a seventeenth embodiment, the present disclosure provides a method ofmaking an extrudable adhesive pouch, the method comprising:

-   -   providing a sealed thermoplastic pouch containing a        polymerizable adhesive precursor composition comprising:        -   a) first components of a first acrylic polymer comprising:            -   i) at least one alkyl (meth)acrylate having from 4 to 22                carbon atoms;            -   ii) at least one of acrylic acid and methacrylic acid;                and        -   b) at least one second acrylic polymer preparable by            polymerization of second components comprising:            -   iii) at least one alkyl (meth)acrylate having from 4 to                22 carbon atoms; iv) at least one (meth)acrylamide                represented by the formula

-   -   -   -   -   wherein R¹ is H or methyl; and

            -   R² and R³ independently represents H or an alkyl group                having from 1 to 8 carbon atoms, or taken together R²                and R³ may form a divalent alkylene group having from 4                to 6 carbon atoms; and

            -   v) at least one high T_(g) macromer having a terminal                free-radically polymerizable unsaturated group, wherein                the high T_(g) macromer has a T_(g) of at least 45° C.;                and

    -   wherein, based on the combined total weight of the components a)        and b), second acrylic polymer b) is present at a level of from        5 to 40 percent by weight; and

at least partially polymerizing the polymerizable adhesive precursorcomposition.

In an eighteenth embodiment, the present disclosure provides a methodaccording to the seventeenth embodiment, wherein the high T_(g) macromerhas a T_(g) of at least 80° C.

In a nineteenth embodiment, the present disclosure provides a methodaccording to the seventeenth or eighteenth embodiment, wherein the atleast one high T_(g) macromer comprises a polymethyl methacrylatemacromer having a terminal free-radically polymerizable unsaturatedgroup.

In a twentieth embodiment, the present disclosure provides a methodaccording to any one of the seventeenth to nineteenth embodiments,wherein based on the total weight of components i) and ii), the firstcomponents comprise:

85 to 99 percent by weight of first component i); and

1 to 15 percent by weight of first component ii).

In a twenty-first embodiment, the present disclosure provides a methodaccording to any one of the seventeenth to twentieth embodiments,wherein based on the total weight of the components iii), iv), and v),the second acrylic polymer comprises:

35 to 90 percent by weight of second component iii);

1 to 10 percent by weight of second component iv); and

5 to 60 percent by weight of second component v).

In a twenty-second embodiment, the present disclosure provides a methodaccording to any one of the seventeenth to twenty-first embodiments,wherein the thermoplastic pouch comprises an ethylene-vinyl acetatecopolymer.

In a twenty-third embodiment, the present disclosure provides a methodaccording to any one of the seventeenth to twenty-second embodiments,wherein the polymerizable adhesive precursor composition furthercomprises at least one of a tackifier and a plasticizer.

Objects and advantages of this disclosure are further illustrated by thefollowing non-limiting examples, but the particular materials andamounts thereof recited in these examples, as well as other conditionsand details, should not be construed to unduly limit this disclosure.

Examples

Unless otherwise noted, all parts, percentages, ratios, etc. in theExamples and the rest of the specification are by weight.

Test Methods: Adhesion Test (180 Degree Peel Strength Test Method)

The adhesive tape was cut into 6 inches (15.2 cm) long by 0.5 inch (1.3cm) wide strips, which were individually applied onto testing substratestainless steel using a 2 kg rubber roller at 12 inches/min (30.5cm/min). The sample was aged overnight in a constant temperature andhumidity (CTH) chamber at 23° C. and 50% relative humidity (RH) beforetesting. Peel strength measurements were made using a force testingapparatus in 180 degree peel mode at 12 inches/min 30.5 cm/min). Datawere recorded as an average of three measurements.

Static Shear Test

Following ASTM Designation: D3654/D3654M-06 (2006) “Standard TestMethods for Shear Adhesion of Pressure-Sensitive Tapes”, a 0.5 inch wide(1.3 cm) strip of adhesive was laminated onto a stainless steel panelusing 4.5 lb roller, covering a 0.5 inch (1.3 cm) by 1 inch (2.5 cm)area of the panel. A 1 kg weight was used as the static load, and thetest samples were placed on an automatic timing apparatus in a CTHchamber conditioned at 23° C./50% RH, and then heated in an oven at 70°C.

Gel Measurement Test

A pre-weighed sample of adhesive was soaked in ethyl acetate overnight.The solution was filtered through a fine mesh screen. A retained portionwas dried and weighed. The gel content was calculated as the ratio ofretained sample to original sample.

Melt Mixing and Hot Press Method (Lab Scale)

The materials with total weight of about 25 grams were mixed in aBrabender mixer at a temperature of 160° C. for 3 minutes at a mixerspeed of 50 rpm. The blend was then pressed for 1 minute in a heatedplaten press with platen temperature of 160° C. between with Mitsubishi3 SAB PET polyester film (50 microns thick) on one side (primed sideagainst the adhesive) and a silicone-coated release liner on the otherside.

Glass Transition Temperature Analysis of Macromonomers Test

Approximately 10 mg of each macromer sample was placed in the base of aTzero pan, a matching Tzero lid was gently placed on top of the sampleand then the lid/base pair was sealed with a Tzero press from TAInstruments (New Castle, Del.). An empty reference pan was alsoprepared, press sealed, and used for a reference for all samples.Samples were transferred by a mechanical arm onto the sample posts in astandard differential scanning calorimeter (DSC, TA Instruments) alongwith the empty reference pan on the opposite post. The temperature wasdropped from room temperature (approximately 20° C.) to the startingtemperature of 0° C. The sample was then heated cycled at 10° C. perminute up to 150° C. (step 1), cooled back to 0° C. at 10° C. per minute(step 2), and once again heated to up to 150° C. at 10° C. per minute(step 3). Glass transition temperatures (T_(g)) were measured on the3^(rd) step so that all sample received identical thermal history priorto the measurement. The T_(g) were identified by analysis of thescanning profile of heat flow versus temperature. The T_(g) is generallyrepresented by a shift in the profile slope upon heating as the heatcapacity of the sample after the transition is altered. The onset T_(g)is recorded as the inflection point of the curve associated with thisshift in heat flow profile at the low temperature end of the shift. Thesample T_(g) values were measured using TA Orchestrator softwareavailable from TA Instruments. The onset T_(g) values are reported inTable 2, below.

Molecular Weight Measurement by Gel Permeation Chromatography (GPC)

Samples were prepared and tested in duplicate. 10 mL of stabilizedtetrahydrofuran (THF) was added to an appropriate mass of each sample togive a solution of approximately 0.25% w/v concentration. The solutionswere swirled for at least 14 hours and then filtered using 0.2 micronPTFE syringe filters.

GPC analysis was conducted using the equipment and conditions reportedin Table 1, below.

TABLE 1 Instrument Agilent 1100 Column set Jordi Gel DVB Mixed Bed, 250× 10 mm I.D. Column Heater 40° C. Eluent THF stabilized with 250 ppm BHTat 1.0 mL/min Injection 30 microliters Detector Differential refractiveindex (DRI)Molecular weights were determined from elution volume by comparison topolystyrene standards. Number average and weight average molecularweights were determined by appropriate weighted integrals of the curveby standard methods.

Macromers Used

Four different macromers of varying molecular weight were used. All wereobtained from Lucite Corporation or ICI (former supplier of Elvacitematerials). All were identified as Elvacite 1010 or 1020, but variouslots were found to have different molecular weights, so the materialswill be identified herein by the following names corresponding to theirmeasured weight average molecular weight (M_(w)) and polydispersitydefined by the ratio of M_(w) to the number average molecular weight,M_(n) as reported in Table 2, below.

TABLE 2 M_(w), POLYDISPERSITY, ONSET T_(g), MACROMER kDaltonsM_(w)/M_(n) ° C. Mac1 4.1 2.3 48.5 Mac2 8.5 1.9 not tested Mac3 13.7 2.483.3 Mac4 25.3 4.5 97.6

TABLE 3 MATERIAL SUPPLIER ABBREVIATION 2-ethyl hexyl acrylate BASF 2EHAacrylic acid Aldrich AA Chemical Co. acrylamide Aldrich ACM Chemical Co.2-octyl acrylate Parchem 2OA n-butyl acrylate Aldrich nBA Chemical Co.Vazo 67 DuPont Irgacure 651 Sartomer ethyl acetate Aldrich EtOAcChemical Co. isopropanol Aldrich IPA Chemical Co. isooctyl thioglycolateAldrich IOTG Chemical Co. Irganox 1076 Ciba Specialty Chemicals

Preparation of Second Acrylic Polymers by Solution Polymerization

The second components, solvent, and initiator were charged to 120 mlamber glass bottles, purged with nitrogen gas at 1.5 L/min for a minimumof 60 seconds to remove oxygen before being sealed with a Teflon linedplastic cap. The sealed bottles were then mounted into a Launder-Ometerwashing machine in which they were immersed in water which was heated to60° C. with mechanical rotation during polymerization which turns thebottles end-over-end. The reaction was allowed to proceed for 24 hoursbefore being removed from the Launder-Ometer washing machine. Bottlecontents were poured onto a silicone release liner that was placedinside of aluminum trays such that the solution thickness was a fewmillimeters. Adhesive solution was allowed to dry at room temperaturefor 3-4 days, flipping the sample over each day until no further solventodor was detected. Each batch contained a total of 35 g of allingredients combined and the ingredients were present in the followingratios based on mass as reported in Table 4, below.

TABLE 4 PARTS BY MATERIALS WEIGHT second components 100 ethyl acetate116 isopropyl alcohol 6.1 Vazo67 (initiator) 0.05

The monomer compositions of the second acrylic polymers prepared aresummarized in the following table for a set of materials containing2-ethyl hexyl acrylate (2EHA), acrylamide (ACM), and macromer (Mac). Themeasured weight average molecular weight is reported in Table 5, below.

TABLE 5 2EHA, ACM, Mac, Mac M_(w), Polymer2 % % % used kDaltons P2-1 955 0 NA 239 P2-2 94.5 5.5 0 NA 253 P2-3 94.5 5.5 0 NA 257 P2-4 90 5 5Mac1 143 P2-5 85 5 10 Mac1 101 P2-6 80 5 15 Mac1 75 P2-7 75 5 20 Mac1 54P2-8 70 5 25 Mac1 40 P2-9 65 5 30 Mac1 28 P2-10 60 5 35 Mac1 23 P2-11 555 40 Mac1 17 P2-12 45 5 50 Mac1 9 P2-13 35 5 60 Mac1 7 P2-14 79.5 8 12.5Mac1 not measured P2-15 75 0 25 Mac1 33 P2-16 90 5 5 Mac2 184 P2-17 80 515 Mac2 124 P2-18 70 5 25 Mac2 88 P2-19 85 5 10 Mac2 158 P2-20 75 5 20Mac2 112 P2-21 65 5 30 Mac2 72 P2-22 90 5 5 Mac3 183 P2-23 85 5 10 Mac3148 P2-24 75 5 20 Mac3 108 P2-25 70 5 25 Mac3 138 P2-26 65 5 30 Mac3 82P2-27 91 4 5 Mac3 179 P2-28 88 7 5 Mac3 191 P2-29 82 5.5 12.5 Mac3 136P2-30 79.5 8 12.5 Mac3 170 P2-31 76 4 20 Mac3 106 P2-32 73 7 20 Mac3 116P2-33 90 5 5 Mac4 205 P2-34 85 5 10 Mac4 180 P2-35 75 5 20 Mac4 144P2-36 65 5 30 Mac4 121 P2-37 82 5.5 12.5 Mac4 142 P2-38 79.5 8 12.5 Mac4254 P2-39 73 7 20 Mac4 198 P2-40 70 5 25 Mac4 131 P2-41 69.4 5.5 25.1Mac4 142

Two more polymers were prepared using n-vinyl-2-pyrrolidone (NVP) orN,N-dimethylacrylamide (NNDMA). Results are reported in Table 6, below.

TABLE 6 2EHA, NVP, NNDMA, Mac, Mac Polymer2 % % % % used P2-42 79.5 8 012.5 Mac3 P2-43 79.5 0 8 12.5 Mac3

Preparation of Second Acrylic Polymers by Bulk Polymerization

Second acrylic polymers in Table 7, below, were prepared according tothe method described in U.S. Pat. No. 5,637,646 (Ellis).

TABLE 7 2EHA, ACM, Mac, Mac M_(w), Polymer2 % % % used kDaltons P2-44 907 3 Mac1 122 P2-45 70 5 25 Mac1 45

Preparation of First Acrylic Polymer by Solution Polymerization

A first acrylic polymer was prepared as described above for preparationof the second acrylic polymer by solution polymerization, except with alarger batch size comprising 250 g of combined ingredients and thepolymerization was conducted in a 1-liter bottle. The ingredients werepresent in amounts as reported in Table 8, below.

TABLE 8 MATERIALS PARTS BY WEIGHT first components 100 ethyl acetate 150IOTG (chain transfer agent) 0.04 Vazo67 (initiator) 0.05

The monomer composition and molecular weight for this polymer isreported in Table 9, below.

TABLE 9 2EHA, AA, M_(w), Polymer1 % % kDaltons P1-1 95 5 312

These polymer solutions were not dried before use.

Preparation of Adhesive Compositions by Solution Blending

For each of the following compositions, a dried second acrylic polymeras described above was dissolved in a portion of the first acrylicpolymer solution P1-1 in a glass jar.

Additional ethyl acetate was added to obtain a final solids content(i.e. non-volatile components) of about 25%. The mixture was allowed tomix on a roller until homogeneous. The mixture was then coated on asample of 50 m thick primed polyester film (Mitsubishi 3 SAB) using aknife coater with a gap set to yield a dry coating thickness of about 50μm. The coated sample was dried in a forced air oven at 70° C. for 10minutes to evaporate the solvent. The samples were conditioned in acontrolled temperature and humidity (CTH) room at 23.4° C. and 50%relative humidity overnight prior to testing. The compositions preparedand their performance test results are reported in Table 10.

Preparation of Adhesive Compositions by Polymerization of First AcrylicPolymer in Presence of Second Acrylic Polymer

For these compositions, the second acrylic polymer was dissolved in thecomponent mixture for preparation of the first acrylic polymer. Thatmixture was sealed in a clear polymer package and polymerized in bulk,using ultraviolet light to initiate the polymerization according to themethod described in U.S. Pat. No. 5,804,610 (Hamer et al.). For samplesE-40 and E-41, the monomer mixture also contained 0.10 pph Irgacure 651(photoinitiator), 0.02 pph IOTG (chain transfer agent), and 0.40 pphIrganox 1076 (antioxidant) where the pph represents parts per hundredparts of monomer. For all the others, the monomer mixture also contained0.15 pph Irgacure 651 and 0.02 pph IOTG and no antioxidant. Afterpolymerization, tape samples were prepared by the Melt Mixing and HotPress method described above. The compositions prepared and theirperformance test results are reported in Table 11.

TABLE 10 Overall 180° Peel Adhesion, Shear Shear Polymer 2, Mac,Adhesion, Failure (23° C.), Shear Failure (70° C.), Shear Failure IDPolymer 2 % % N/cm mode min mode (23° C.) min mode 70° C. C-7 None 0 020.4 cohesive 2 cohesive 0 cohesive C-8 P2-3 40 0 7.8 adhesive 22cohesive 2 cohesive E-42 P2-14 30 3.75 10.4 adhesive 200 cohesive 7cohesive E-43 P2-14 40 5 7.6 adhesive 1581 cohesive 13 cohesive E-44P2-8 30 7.5 9.3 adhesive 140 cohesive 6 cohesive E-45 P2-8 40 10 9.9adhesive 988 cohesive 6 cohesive E-46 P2-10 30 10.5 14.8 adhesive 62cohesive 2 cohesive E-47 P2-10 40 14 9.2 adhesive 271 cohesive 4cohesive E-48 P2-30 30 3.75 7.7 adhesive 7652 cohesive 373 cohesive E-49P2-32 30 6 6.8 adhesive ≧10000 cohesive 402 cohesive E-50 P2-25 30 7.56.4 adhesive 2423 cohesive 397 cohesive E-51 P2-38 30 3.75 5.9 adhesive4966 cohesive 265 cohesive E-52 P2-39 30 6 7.2 adhesive 4776 cohesive241 cohesive E-53 P2-40 30 7.5 6.9 adhesive 6151 cohesive 495 cohesiveC-9 P2-42 30 3.75 18.7 cohesive 908 cohesive 13 cohesive C-10 P2-43 303.75 17.2 cohesive 182 cohesive 8 cohesive

TABLE 11 Shear Overall Polymer 1 180° Peel Shear Failure Shear Polymer2, Mac, Polymer 1 component Adhesion, (23° C.), mode (70° C.), ShearFailure ID Polymer 2 % % components Ratios N/cm min (23° C.) min mode70° C. C-1 0 0 2-OA/AA 90/10 7.0 211 cohesive 11 cohesive C-2 0 02-EHA/AA 95/5 9.2 3 cohesive 1 cohesive C-3 0 0 2-OA/AA 95/5 4.0 15cohesive 2 cohesive E-1 P2-6 20 3 2-OA/AA 90/10 7.6 ≧10000 96 cohesiveE-2 P2-4 25 1.25 2-OA/AA 90/10 7.3 1239 cohesive 36 cohesive E-3 P2-5 252.5 2-OA/AA 90/10 7.2 8404 cohesive 63 cohesive E-4 P2-7 25 5 2-OA/AA90/10 6.4 ≧10000 429 cohesive E-5 P2-9 25 7.5 2-OA/AA 90/10 6.5 ≧100001369 cohesive E-6 P2-11 25 10 2-OA/AA 90/10 4.5 ≧10000 1960 cohesive E-7P2-12 25 12.5 2-OA/AA 90/10 6.6 ≧10000 269 cohesive E-8 P2-13 25 152-OA/AA 90/10 6.2 ≧10000 35 cohesive C-4 25 0 2-EHA/AA 95/5 6.5 22cohesive 2 cohesive E-9 P2-5 25 2.5 2-EHA/AA 95/5 6.8 320 cohesive 13cohesive E-10 P2-7 25 5 2-EHA/AA 95/5 6.4 ≧10000 237 cohesive E-11 P2-925 7.5 2-EHA/AA 95/5 6.0 ≧10000 2998 cohesive C-5 25 6.25 2-EHA/AA 95/55.9 2090 121 E-12 P2-16 30 1.5 2-OA/AA 95/5 3.9 320 cohesive 10 cohesiveE-13 P2-17 30 4.5 2-OA/AA 95/5 2.8 6164 cohesive 270 cohesive E-14 P2-1830 7.5 2-OA/AA 95/5 2.2 8607 cohesive 523 cohesive E-15 P2-16 30 1.52-OA/AA 90/10 5.1 2994 cohesive 43 cohesive E-16 P2-17 30 4.5 2-OA/AA90/10 4.6 ≧10000 1683 cohesive E-17 P2-18 30 7.5 2-OA/AA 90/10 2.9≧10000 1145 cohesive E-18 P2-17 10 1.5 2-OA/AA 90/10 7.7 2440 cohesive72 cohesive E-19 P2-18 10 2.5 2-OA/AA 90/10 7.1 7874 cohesive 355cohesive E-20 P2-16 25 1.25 2-EHA/AA 95/5 6.2 114 cohesive 17 cohesiveE-21 P2-19 25 2.5 2-EHA/AA 95/5 5.8 2318 cohesive 143 cohesive E-22P2-20 25 5 2-EHA/AA 95/5 5.0 7806 cohesive 646 cohesive E-23 P2-21 257.5 2-EHA/AA 95/5 4.1 ≧10000 cohesive 2023 cohesive E-24 P2-22 25 1.252-EHA/AA 95/5 6.0 127 cohesive 10 cohesive E-25 P2-23 25 2.5 2-EHA/AA95/5 5.8 1189 cohesive 109 cohesive E-26 P2-24 25 5 2-EHA/AA 95/5 4.64993 cohesive 573 cohesive E-27 P2-26 25 7.5 2-EHA/AA 95/5 4.2 ≧100001378 cohesive C-6 20 0 2-EHA/AA 95/5 7.2 25 cohesive 3 cohesive E-28P2-27 40 2 2-EHA/AA 95/5 6.2 899 cohesive 61 cohesive E-29 P2-28 30 1.52-EHA/AA 95/5 6.2 1995 cohesive 78 cohesive E-30 P2-29 30 3.75 2-EHA/AA95/5 6.0 8703 cohesive 524 cohesive E-31 P2-29 33 4.125 2-EHA/AA 95/55.2 ≧10000 1943 cohesive E-32 P2-30 30 3.75 2-EHA/AA 95/5 4.9 ≧100001617 cohesive E-33 P2-31 30 6 2-EHA/AA 95/5 4.4 6096 cohesive 797cohesive E-34 P2-33 25 1.25 2-EHA/AA 95/5 5.8 61 cohesive 3 cohesiveE-35 P2-34 25 2.5 2-EHA/AA 95/5 5.6 84 cohesive 8 cohesive E-36 P2-35 255 2-EHA/AA 95/5 5.2 213 cohesive 28 cohesive E-37 P2-36 25 7.5 2-EHA/AA95/5 5.4 92 cohesive 11 cohesive E-38 P2-37 30 3.75 2-EHA/AA 95/5 4.9643 cohesive 67 cohesive E-39 P2-41 20 5.02 2-EHA/AA 95/5 4.4 1256cohesive 137 cohesive E-40 P2-44 30 0.9 2-EHA/AA 95/5 1789 cohesive E-41P2-45 30 7.5 2-EHA/AA 95/5 7084 cohesive 776 cohesive

All cited references, patents, and patent applications in the aboveapplication for letters patent are herein incorporated by reference intheir entirety in a consistent manner. In the event of inconsistenciesor contradictions between portions of the incorporated references andthis application, the information in the preceding description shallcontrol. The preceding description, given in order to enable one ofordinary skill in the art to practice the claimed disclosure, is not tobe construed as limiting the scope of the disclosure, which is definedby the claims and all equivalents thereto.

What is claimed is:
 1. A method of making an adhesive composition, themethod comprising mixing at least one first acrylic polymer with atleast one second acrylic polymer in the presence of organic solvent,wherein: each first acrylic polymer is preparable by free-radicalpolymerization of first components comprising: i) at least one alkyl(meth)acrylate having from 4 to 22 carbon atoms; and ii) at least one ofacrylic acid and methacrylic acid; each second acrylic polymer ispreparable by polymerization of second components comprising: iii) atleast one alkyl (meth)acrylate having from 4 to 22 carbon atoms; iv) atleast one (meth)acrylamide represented by the formula

wherein R¹ is H or methyl; and R² and R³ independently represents H oran alkyl group having from 1 to 8 carbon atoms, or taken together R² andR³ may form a divalent alkylene group having from 4 to 6 carbon atoms;and v) at least one high T_(g) macromer having a terminal free-radicallypolymerizable unsaturated group, wherein the high T_(g) macromer has aT_(g) of at least 45° C., wherein based on the combined total weight ofthe at least one first acrylic polymer and the at least one secondacrylic polymer, the at least one second acrylic polymer is present at alevel of from 5 to 40 percent by weight.
 2. An adhesive compositioncomprising a polymerized reaction product of components comprising: a)first components of a first acrylic polymer comprising: i) at least onealkyl (meth)acrylate having from 4 to 22 carbon atoms; ii) at least oneof acrylic acid and methacrylic acid; b) at least one second acrylicpolymer preparable by polymerization of second components comprising:iii) at least one alkyl (meth)acrylate having from 4 to 22 carbon atoms;iv) at least one (meth)acrylamide represented by the formula

wherein R¹ is H or methyl; and R² and R³ independently represents H oran alkyl group having from 1 to 8 carbon atoms, or taken together R² andR³ may form a divalent alkylene group having from 4 to 6 carbon atoms;and v) at least one high T_(g) macromer having a terminal free-radicallypolymerizable unsaturated group, wherein the high T_(g) macromer has aT_(g) of at least 45° C.; and wherein, based on the combined totalweight of the components a) and b), second acrylic polymer b) is presentat a level of from 5 to 40 percent by weight.
 3. The adhesivecomposition of claim 2, wherein the high T_(g) macromer has a T_(g) ofat least 80° C.
 4. The adhesive composition of claim 2, wherein the atleast one high T_(g) macromer comprises a polymethyl methacrylatemacromer having a terminal free-radically polymerizable unsaturatedgroup.
 5. The adhesive composition of claim 2, wherein based on thetotal weight of components i) and ii), the first components comprise: 85to 99 percent by weight of first component i); and 1 to 15 percent byweight of first component ii).
 6. The adhesive composition of claim 2,wherein based on the total weight of the components iii), iv), and v),the second acrylic polymer comprises: 30 to 94 percent by weight ofsecond component iii); 1 to 10 percent by weight of second componentiv); and 5 to 60 percent by weight of second component v).
 7. Theadhesive composition of claim 2, wherein based on the total weight ofthe adhesive composition, the macromer comprises from 1 to 15 percent byweight of the adhesive composition.
 8. An extrudable adhesive pouchcomprising the adhesive composition of claim 2, sealed within athermoplastic pouch.
 9. The extrudable adhesive pouch of claim 8,wherein the thermoplastic pouch comprises an ethylene-vinyl acetatecopolymer.
 10. A method of making an extrudable adhesive pouch, themethod comprising: providing a sealed thermoplastic pouch containing apolymerizable adhesive precursor composition comprising: a) firstcomponents of a first acrylic polymer comprising: i) at least one alkyl(meth)acrylate having from 4 to 22 carbon atoms; ii) at least one ofacrylic acid and methacrylic acid; and b) at least one second acrylicpolymer preparable by polymerization of second components comprising:iii) at least one alkyl (meth)acrylate having from 4 to 22 carbon atoms;iv) at least one (meth)acrylamide represented by the formula

wherein R¹ is H or methyl; and R² and R³ independently represents H oran alkyl group having from 1 to 8 carbon atoms, or taken together R² andR³ may form a divalent alkylene group having from 4 to 6 carbon atoms;and v) at least one high T_(g) macromer having a terminal free-radicallypolymerizable unsaturated group, wherein the high T_(g) macromer has aT_(g) of at least 45° C.; and wherein, based on the combined totalweight of the components a) and b), second acrylic polymer b) is presentat a level of from 5 to 40 percent by weight; and at least partiallypolymerizing the polymerizable adhesive precursor composition.
 11. Themethod of claim 10, wherein the high T_(g) macromer has a T_(g) of atleast 80° C.
 12. The method of claim 10, wherein the at least one highT_(g) macromer comprises a polymethyl methacrylate macromer having aterminal free-radically polymerizable unsaturated group.
 13. The methodof claim 10, wherein based on the total weight of components i) and ii),the first components comprise: 85 to 99 percent by weight of firstcomponent i); and 1 to 15 percent by weight of first component ii). 14.The method of claim 10, wherein based on the total weight of thecomponents iii), iv), and v), the second acrylic polymer comprises: 30to 94 percent by weight of second component iii); 1 to 10 percent byweight of second component iv); and 5 to 60 percent by weight of secondcomponent v).
 15. The method of claim 10, wherein the thermoplasticpouch comprises an ethylene-vinyl acetate copolymer.
 16. The method ofclaim 10, wherein based on the total weight of the adhesive composition,the macromer comprises from 1 to 15 percent by weight of the adhesivecomposition.